Ch 2 Chemical Level of Organization Flashcards
Chemistry
the structure and interactions of all living matter
Matter
is anything that takes space and adds mass
3 states: solid, liquid, gas
Mass
is the amount of matter in an object
Mass does not change, weight does
Chemical elements
cannot be split into simpler substances
There are 118 elements, 92 occur naturally on Earth
Chemical symbols
consist of 1 or 2 letters of the elements name. Ex: Carbon=C, Oxygen=O, Hydrogen=H
Major Elements
make up 96% of body’s mass, they are oxygen(O), carbon, hydrogen(H), nitrogen(N)
Lesser elements
make up 3.6% body mass, calcium, phosphorus (P), potassium (K), sulfur (S), sodium chlorine (CI), magnesium (Mg), iron (Fe)
Atoms
smallest unit of matter, retain properties and characteristics of the element
Subatomic particles
compose individual atoms, they are protons, neutrons, and electrons
Protons
Positive charge
Neutron
no charge
Electron
negative charge
Electron shells
are circles around the nucleus that electrons orbit around.
Electrons fill into the shell in a specific order, innermost to outermost.
The number of electrons in an atom always equals the number of protons, each Atom is electrically neutral with a 0 charge
Atomic number
number of protons
Mass number
sum of protons and neutrons
Isotopes
are atoms with the same number of protons but different number of neutrons, this gives the atom a different mass number. Most isotopes are stable.
Radioactive Isotopes
are unstable and decay, releasing radiation.
They can transform into other elements when they decay. They can decay in 1 second or a million years
Half-life
half life of an isotope is the time it takes for half of the radioactive atoms in a sample to decay into a stable form
Dalton
(amu) is the unit used to measure atomic mass
Neutron has 1.008 dalton, proton has 1.007 dalton, electron has 0.0005 dalton
Atomic Mass
is the average mass of all naturally occurring isotopes
Ions
atoms that give up or gain an electron. Ex: Ca2+ stands for calcium with 2 positive charges b/c it lost 2 electrons
Ionization
the process of giving up or gaining an electron
Molecules
are when atoms share 2 electrons, chemically bonded
Compounds
contain atoms of 2 or more different elements. Ex: H2O and NaCI (sodium chloride
Free Radical
atom or group of atoms with an unpaired electron in outermost shell. These are unstable, highly reactive, and destructive. They become stable when they gain an electron or give the unpaired one away
Chemical Bonds
are forces that hold together atoms and molecules
Valence Shell
outermost shell, determines if atoms will form chemical bonds based on the number of electrons. If an atom is chemically stable it will not bond with another
Octet Rule
observation that elements tend to bond in such a way that each atom has eight electrons in its valence shell
Types of Chemical Bonds
ionic, covalent, hydrogen
Ionic Bonds
The force that holds together ions with opposite charges
Cation
positively charged ion, they lose an electron, ending up with more protons than electrons
Anion
negatively charged ion, they gain an electron, ending up with more electrons than protons
Covalent Bonds
Forms when 2 or more atoms share an electron. The larger the number of electrons shared, the stronger the bond
Single Covalent Bond
two atoms share one electron
Double Covalent Bond
two atoms share 2 pairs of electrons
Nonpolar Covalent Bond
two atoms share their electrons equally
Polar Covalent Bond
the electrons shared between two atoms is unequal
Electronegativity
the power to attract electrons to itself
Hydrogen Bonds
Forms when a hydrogen atom with a partial positive attracts the partial negative of near by atoms
Chemical Reaction
Occurs when new bonds form or old ones break
Reactants
the starting substance, Ex: H2 and O2
Products
the end product, Ex: H2O
Metabolism
all the chemical reactions occurring in the body.
Potential Energy
energy stored by matter due to its position
Kinetic Energy
energy associated with the matter in motion
Chemical Energy
form of potential energy stored in bonds of compounds and molecules
Law of Conservation of Energy
energy cannot be created or destroyed, but converted from one form to another
Exergonic reactions
release more energy than they absorb
Endergonic reactions
absorb more energy than they release.
activation energy
The collision energy needed to break the chemical bonds of the reactants
Concentration
The more particles of matter present in a confined space, the greater the chance that they will collide
Temperature
As temperature rises, particles of matter move about more rapidly
Catalysts
chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur
Synthesis (anabolism)
2 or more atoms, ions, molecules combine to form larger molecules, synthesis means to put together
A+B = AB
Decomposition (catabolism
splits larger molecules into smaller ones
AB= A+B
Exchange
consists of synthesis and decomposition, switches partners
AB+CD= AD+BC
Reversible
products can revert back to original reactants
AB = A+B and A+B = AB
Oxidation-Reduction
breaks down food molecules to produce energy. Oxidation loses electrons and Reduction gains electrons. When one is oxidized the other is reduced at same time
Inorganic Compounds
Lacks carbon, few atoms, cannot be used by cells for complicated functions, include water, salts, acids, and bases. Water is the most important inorganic compound.
Makes up 55-60% of body,
Inorganic compounds with carbon: carbon dioxide, bicarbonate, carbonic acid
Organic Compounds
contain carbon, usually contain hydrogen, always has covalent bond. Large molecules made of long carbon atom chains
Makes up 38-43% of body
Water
Most important compound in all living things. High polarity. Versatile solvent. Cohesive and can resist temp changes (high heat capacity)
Solvent
does the dissolving. ex: water
Solute
whats being dissolved. ex: salt
Hydrophilic
water loving ex: salt or sugar
hydrophobic
scared of water ex: oil/fats
Dehydration synthesis
2 smaller molecules form larger, loss of water
Mixture
compounds blended together but not bonded. Ex: air is made of nitrogen, oxygen, argon, carbon dioxide
3 types: solutions, colloids, suspensions
Colloid
substance microscopically dispersed evenly throughout another substance. Appears translucent or opaque Ex: milk
Suspension
can mix with liquid but will separate, ex: blood plasma
Mass per volume
gives relative mass of solute found in volume of solution, Ex: “Alcohol 1% by volume”
Moles
(mol/L) amount of substance that has mass in grams equal to sum of atomic mass in all atoms. Ex: 1 mole of chlorine (atomic mass= 35.45) is 35.45
Avogardros number is 6.023 x 10^23
Moles tell about # of atoms, ions or molecules present
Dissociate
acids, bases, salts dissolve and separate into ions and surrounds by water molecules
Acids
breaks off into hydrogen ions and anions, proton donor pH scale 1-6
Bases
removes hydrogen, proton acceptor
Salt
dissociates to cations and anions, electrolytes for carrying electrical currents
pH scale
1-6 is acidic, 8-10 is a base, 7 is neutral
Buffer System
convert strong acids/bases to weak ones
Maintenance of body fluid homeostasis is critical
Carbon
organic compounds always contain carbon
Carbon can combine into many shapes
Carbon compounds do not dissolve easy in water
Carbon is good source of energy
Macromolecules
small organic molecules combined into large ones
Monomers
mono=one
the reaction that joins two monomers is a dehydration synthesis
polymers
Poly=many, mers=parts
large molecule formed by the covalent bonding of many identical or similar small building‐block molecules called monomers
Carbohydrate
“Watered carbon”
Includes sugars, glycogen, starches, and cellulose
Primary source of energy
Carbon, hydrogen, and oxygen are elements in carbs
3 groups: monosaccharides, disaccharides, polysaccharides
monosaccharides
simple sugar, cannot be decomposed to simpler sugar, contain 3-7 carbon atoms
Glucose Fructose(fruits) Galactose (milk sugar) Deoxyribose (DNA) Ribose(RNA)
disaccharide
2 or more monosaccharides
Sucrose (table sugar glucose+fructose), Lactose (milk sugar glucose+galactose)
Maltose (glucose+glucose)
polysaccharides
tens to hundreds monosaccharides
Glycogen, Starch, Cellulose
lipids
fats
hydrophobic
Types: fatty acids, triglycerides (fats and oils), phospholipids, steroids (ring of carbon atoms), eicosanoids (20 carbon lipids), fat soluble vitamins, lipoproteins
Fatty Acids
synthesize phospholipids and triglycerides, can be saturated or unsaturated
Saturated
contains one covalent bond, solid at room temp
Unsaturated
one or more double covalent bonds, liquid at room temp
Triglycerides
provide protection, insulation, energy
glycerol forms backbone of triglyceride
Solid or liquid at room temp
Phospholipids
important in cell membranes
The “head: is hydrophilic
The “tail” is hydrophobic
Considered amphipathic (both polar and nonpolar)
Steroids
includes all the sex hormones, adrenal cortical hormones, bile acids
proteins
Give structure to body, regulate processes, provide protection, assist in muscle contraction, transport substances, serve as enzymes
Contain carbon, hydrogen, oxygen, nitrogen. Some contain sulfur
amino acids
20 different amino acids, building blocks for protein
The covalent bond joining 2 amino acids makes a peptide bond
2 amino acids combine making a dipeptide, 3 make a tripeptide
10-2000 or more amino acids make polypeptide
Enzymes
A catalyst in a living cell, highly specific, extremely efficient, subject to cellular controls, #1 Catalyst**
Protein part is called apoenzyme, non protein part is called cofactor
Nucleic Acids
Make up DNA and RNA
Chain of repeating monomers called nucleotides
DNA
forms genetic code in nuclei of cells and regulates most of the cells activities
RNA
guides protein formation, relays instruction
Nitrogenous base
4 different bases, adenine (A), thymine (T), cytosine [C], guanine (G)
A & T pair, C & G pair
Pentose Sugar
five carbon sugar attached to base in DNA
Phosphate group
form backbone of DNA
Adenosine Triphosphate (ATP)
Principle energy storing molecule in the body
Usable energy is in 3rd phosphate
ATP is formed during cellular respiration
ATPases control the release of ATP
ATP moves ions across membrane during active transport
ATP is used in contraction of muscles
